Real-Time and Accurate Target Location Method Based on Artificial Mark

A real-time and accurate target location method based on the artificial mark is proposed in the applications of wheelchair nursing bed docking. The artificial mark consists of the lines and the circles. Target-oriented edge detection is realized by using the modified Sobel operator, and morphology filtering is used to realize the edge extraction of the artificial mark area. The image segmentation is achieved based on the extracted edge image. In addition, location accurately on the segmented image is realized by using the method of the gravity center. The experimental results show that the subpixel level location is achieved under the complex background. The accuracy of the location method is less than 5 mm, and the location process takes 36 ms.